James Webb Telescope - Page 28

ynot · 20th July 2022, 02:43 PM

Never mind space expansion, the (observable by telescope) Universe gets bigger every time JWST blinks

.

Shepherd · 20th July 2022, 03:09 PM

The image released showing the most distance galaxies was made from a 12.5 hour exposure, iirc, whereas similar images from Hubble require approximately 10 day exposures. So, scientists are pretty excited as to what (future) longer exposures on the JWST will show.

Trebuchet · 20th July 2022, 04:40 PM

Oh-M-Gee, it's been totally ruined by micrometorite damage!!!! Eleventy!

According to the lamestream media.

Somehow, it'll go on doing useful science for years to come.

Samson · 20th July 2022, 04:57 PM

Originally Posted by Mike Helland

JWST has found the oldest galaxy we have ever seen in the universe

Discoveries from the James Webb Space Telescope are pouring in, with an analysis of the latest data revealing a galaxy that dates back to just 300 million years after the big bang – the oldest we have ever seen

https://www.newscientist.com/article...-the-universe/

It looks just like a boil needing lancing lol, I presume that picture is somehow best guess at true colour.

Skeptic Ginger · 20th July 2022, 05:08 PM

Originally Posted by Samson

It looks just like a boil needing lancing lol, I presume that picture is somehow best guess at true colour.

Or they are using redshift.

Puppycow · 20th July 2022, 05:25 PM

Originally Posted by Samson

I presume that picture is somehow best guess at true colour.

Not exactly. First of all, what would "true" color actually mean? The color that the light was when it was emitted (before being red-shifted into the infrared, which human eyes cannot see)? But probably you map longer wavelengths onto the red end of the visible spectrum and shorter wavelengths onto the blue end. So in that sense, the colors would correspond to how our own eyes perceive different wavelengths of visible light.

ynot · 20th July 2022, 06:09 PM

Originally Posted by Samson

It looks just like a boil needing lancing lol, I presume that picture is somehow best guess at true colour.

I thought it was a whitehead pimple on God's butt. If they pan around a bit we might see God's Black Hole

.

arthwollipot · 20th July 2022, 07:12 PM

Originally Posted by Puppycow

Not exactly. First of all, what would "true" color actually mean? The color that the light was when it was emitted (before being red-shifted into the infrared, which human eyes cannot see)? But probably you map longer wavelengths onto the red end of the visible spectrum and shorter wavelengths onto the blue end. So in that sense, the colors would correspond to how our own eyes perceive different wavelengths of visible light.

Presumably you could blue shift the entire spectrum into the visible light range, keeping the proportions between the frequencies the same. A computer algorithm could do it, based on the known about of red shift in the source.

Puppycow · 21st July 2022, 04:10 AM

Originally Posted by arthwollipot

Presumably you could blue shift the entire spectrum into the visible light range, keeping the proportions between the frequencies the same. A computer algorithm could do it, based on the known about of red shift in the source.

That makes a lot of sense to me. Just cancel out the red-shift, right? You can probably also work out what visible light waves would be present from the infrared waves and known physics of blackbody radiation. And I know that they use emission lines of elements to calculate how much red shift there is.

Samson · 21st July 2022, 04:25 AM

What I hope they have done here is compile a colour visual as though as close as Andromeda today, but I am a little uncertain.

Mike Helland · 21st July 2022, 11:10 AM

Related paper to the ultra distant galaxies:

https://arxiv.org/abs/2207.09434

"This, in turn, suggests that future deep JWST observations may identify relatively bright galaxies to much earlier epochs than might have been anticipated."

arthwollipot · 21st July 2022, 06:57 PM

Originally Posted by Puppycow

That makes a lot of sense to me. Just cancel out the red-shift, right? You can probably also work out what visible light waves would be present from the infrared waves and known physics of blackbody radiation. And I know that they use emission lines of elements to calculate how much red shift there is.

Yes, that's how it seems to me. Kind of like how noise-cancelling headphones work but not really.

Jack by the hedge · 22nd July 2022, 03:42 AM

Originally Posted by arthwollipot

Yes, that's how it seems to me. Kind of like how noise-cancelling headphones work but not really.

Perhaps more like how a bat detector works by shifting the bat's calls down to human-audible frequencies. Though of course here the shift would be raising the frequencies to be closer to what they were when originally emitted.

What I'm not clear about is whether that's really something that Webb can do: is the degree of redshift seen in those very distant galaxies suitable for Webb's sensors to see what was originally visible wavelengths and allow the production of a false colour image close to what was originally true colour?

(And that's aside from whether that would be a scientifically useful thing to do or just a cool trick.)

Puppycow · 22nd July 2022, 04:00 AM

This whole discussion reminds me that I did come across a video just the other day from a guy that did his own image processing on the data. He also shows how to do it, for anyone who is curious. I only watched bits and pieces of it myself, but for anyone who is interested in image processing, colorizing and so on, here is the video:

https://www.youtube.com/watch?v=DVuonz26P0w

He also shows where you can download the raw data, and how to find the data you are looking for. Anyone can do it, but there's a firehose of data so it helps to know how to narrow it down.

jadebox · 22nd July 2022, 06:01 AM

A "true color" image would expose less detail and probably wouldn't look like what a person would actually see. Ignoring issues of distance, perspective, and brightness, color perception depends on more than just the frequency of the light being observed. Think about that "what color is the dress" meme and other optical illusions.

I am not sure there is much to be gained by trying to produce a true color image. But, it might be an interesting exercise.

Back in the days before such data was easily available on the Internet, I bought a big set of CDROMs of data from the Voyager missions. It included software, with source code, for displaying the image. I had fun playing with and modifying the software. It was fun seeing the images slowly rendering on the screen.

ynot · 28th July 2022, 04:08 PM

Other than the "eye candy" images, my main lay-interests in JWST are evidence that life might exists elsewhere, and evidence that either supports The Big Bang/expanding Universe model or not. I also expect "at the length truth will out", so I don't need to worry about Standard Model bias conspiracies.

I imagine (hope) there will be a deep space image that uses JWST's highest resolution and magnification at the longest exposure to see the full extent of how far it can see and what's there (well, what was there when the light/heat was emitted).

ynot · 2nd August 2022, 12:50 PM

JWST Next Steps . . . https://blogs.nasa.gov/webb/2022/08/...bs-next-steps/

ETA - Eye candy . . . https://www.nasa.gov/feature/goddard...rtwheel-galaxy . . . Yummy!

JWST = Just Wow! Space Telescope

ynot · 2nd August 2022, 04:21 PM

Oooops - wrong thread.

Jack by the hedge · 4th August 2022, 04:31 AM

Does this thread about the JWST need a major split? The cosmology discussion probably deserves a thread of its own.

sarge · 5th August 2022, 03:54 AM

Fascinating discussion about the impact of JWST findings on existing theories moved to http://www.internationalskeptics.com...d.php?t=360724

Posted By:sarge

Mike Helland · Yesterday, 11:23 PM

A video from ESA, 1 minute long, "Zoom into the Cartwheel Galaxy":

https://www.youtube.com/watch?v=bfAjQX-eapc

YouTube Video This video is not hosted by the ISF. The ISF can not be held responsible for the suitability or legality of this material. By clicking the link below you agree to view content from an external website.

I AGREE

20th July 2022, 02:43 PM	#1081
ynot Philosopher Join Date: Jan 2006 Location: Present Posts: 9,214	Never mind space expansion, the (observable by telescope) Universe gets bigger every time JWST blinks .
	__________________ Paranormal/supernatural beliefs are knowledge placebos. Rumours of a god’s existence have been greatly exaggerated. Make beliefs truths and you get make-believe truths.

20th July 2022, 03:09 PM	#1082
Shepherd Critical Thinker Join Date: Oct 2014 Posts: 403	The image released showing the most distance galaxies was made from a 12.5 hour exposure, iirc, whereas similar images from Hubble require approximately 10 day exposures. So, scientists are pretty excited as to what (future) longer exposures on the JWST will show.
Shepherd Critical Thinker Join Date: Oct 2014 Posts: 403

20th July 2022, 04:40 PM	#1083
Trebuchet Penultimate Amazing Join Date: Nov 2003 Location: Port Townsend, Washington Posts: 34,432	Oh-M-Gee, it's been totally ruined by micrometorite damage!!!! Eleventy! According to the lamestream media. Somehow, it'll go on doing useful science for years to come.
	__________________ Cum catapultae proscribeantur tum soli proscripti catapultas habeant.

20th July 2022, 05:25 PM	#1086
Puppycow Penultimate Amazing Join Date: Jan 2003 Location: Yokohama, Japan Posts: 27,251	Originally Posted by Samson I presume that picture is somehow best guess at true colour. Not exactly. First of all, what would "true" color actually mean? The color that the light was when it was emitted (before being red-shifted into the infrared, which human eyes cannot see)? But probably you map longer wavelengths onto the red end of the visible spectrum and shorter wavelengths onto the blue end. So in that sense, the colors would correspond to how our own eyes perceive different wavelengths of visible light.
	__________________ A fool thinks himself to be wise, but a wise man knows himself to be a fool. William Shakespeare

20th July 2022, 06:09 PM	#1087
ynot Philosopher Join Date: Jan 2006 Location: Present Posts: 9,214	Originally Posted by Samson It looks just like a boil needing lancing lol, I presume that picture is somehow best guess at true colour. I thought it was a whitehead pimple on God's butt. If they pan around a bit we might see God's Black Hole .
	__________________ Paranormal/supernatural beliefs are knowledge placebos. Rumours of a god’s existence have been greatly exaggerated. Make beliefs truths and you get make-believe truths.

20th July 2022, 04:57 PM	#1084
Samson Penultimate Amazing Join Date: Oct 2013 Posts: 10,019	Originally Posted by Mike Helland JWST has found the oldest galaxy we have ever seen in the universe Discoveries from the James Webb Space Telescope are pouring in, with an analysis of the latest data revealing a galaxy that dates back to just 300 million years after the big bang – the oldest we have ever seen https://www.newscientist.com/article...-the-universe/ It looks just like a boil needing lancing lol, I presume that picture is somehow best guess at true colour.

20th July 2022, 05:08 PM	#1085
Skeptic Ginger Nasty Woman Join Date: Feb 2005 Posts: 92,445	Originally Posted by Samson It looks just like a boil needing lancing lol, I presume that picture is somehow best guess at true colour. Or they are using redshift.

20th July 2022, 07:12 PM	#1088
arthwollipot Observer of Phenomena Pronouns: he/him Join Date: Feb 2005 Location: Ngunnawal Country Posts: 77,487	Originally Posted by Puppycow Not exactly. First of all, what would "true" color actually mean? The color that the light was when it was emitted (before being red-shifted into the infrared, which human eyes cannot see)? But probably you map longer wavelengths onto the red end of the visible spectrum and shorter wavelengths onto the blue end. So in that sense, the colors would correspond to how our own eyes perceive different wavelengths of visible light. Presumably you could blue shift the entire spectrum into the visible light range, keeping the proportions between the frequencies the same. A computer algorithm could do it, based on the known about of red shift in the source.
	__________________ This is Australia. It's possible to start a fire with a lukewarm audience reaction to your standup routine.

21st July 2022, 04:10 AM	#1089
Puppycow Penultimate Amazing Join Date: Jan 2003 Location: Yokohama, Japan Posts: 27,251	Originally Posted by arthwollipot Presumably you could blue shift the entire spectrum into the visible light range, keeping the proportions between the frequencies the same. A computer algorithm could do it, based on the known about of red shift in the source. That makes a lot of sense to me. Just cancel out the red-shift, right? You can probably also work out what visible light waves would be present from the infrared waves and known physics of blackbody radiation. And I know that they use emission lines of elements to calculate how much red shift there is.
	__________________ A fool thinks himself to be wise, but a wise man knows himself to be a fool. William Shakespeare

21st July 2022, 04:25 AM	#1090
Samson Penultimate Amazing Join Date: Oct 2013 Posts: 10,019	What I hope they have done here is compile a colour visual as though as close as Andromeda today, but I am a little uncertain.

21st July 2022, 11:10 AM	#1091
Mike Helland Master Poster Join Date: Nov 2020 Posts: 2,569	Related paper to the ultra distant galaxies: https://arxiv.org/abs/2207.09434 "This, in turn, suggests that future deep JWST observations may identify relatively bright galaxies to much earlier epochs than might have been anticipated."

21st July 2022, 06:57 PM	#1092
arthwollipot Observer of Phenomena Pronouns: he/him Join Date: Feb 2005 Location: Ngunnawal Country Posts: 77,487	Originally Posted by Puppycow That makes a lot of sense to me. Just cancel out the red-shift, right? You can probably also work out what visible light waves would be present from the infrared waves and known physics of blackbody radiation. And I know that they use emission lines of elements to calculate how much red shift there is. Yes, that's how it seems to me. Kind of like how noise-cancelling headphones work but not really.
	__________________ This is Australia. It's possible to start a fire with a lukewarm audience reaction to your standup routine.

22nd July 2022, 03:42 AM	#1093
Jack by the hedge Safely Ignored Join Date: Oct 2009 Posts: 13,577	Originally Posted by arthwollipot Yes, that's how it seems to me. Kind of like how noise-cancelling headphones work but not really. Perhaps more like how a bat detector works by shifting the bat's calls down to human-audible frequencies. Though of course here the shift would be raising the frequencies to be closer to what they were when originally emitted. What I'm not clear about is whether that's really something that Webb can do: is the degree of redshift seen in those very distant galaxies suitable for Webb's sensors to see what was originally visible wavelengths and allow the production of a false colour image close to what was originally true colour? (And that's aside from whether that would be a scientifically useful thing to do or just a cool trick.)

22nd July 2022, 04:00 AM	#1094
Puppycow Penultimate Amazing Join Date: Jan 2003 Location: Yokohama, Japan Posts: 27,251	This whole discussion reminds me that I did come across a video just the other day from a guy that did his own image processing on the data. He also shows how to do it, for anyone who is curious. I only watched bits and pieces of it myself, but for anyone who is interested in image processing, colorizing and so on, here is the video: https://www.youtube.com/watch?v=DVuonz26P0w He also shows where you can download the raw data, and how to find the data you are looking for. Anyone can do it, but there's a firehose of data so it helps to know how to narrow it down.
	__________________ A fool thinks himself to be wise, but a wise man knows himself to be a fool. William Shakespeare

22nd July 2022, 06:01 AM	#1095
jadebox Master Poster Join Date: Sep 2004 Location: USA Posts: 2,255	A "true color" image would expose less detail and probably wouldn't look like what a person would actually see. Ignoring issues of distance, perspective, and brightness, color perception depends on more than just the frequency of the light being observed. Think about that "what color is the dress" meme and other optical illusions. I am not sure there is much to be gained by trying to produce a true color image. But, it might be an interesting exercise. Back in the days before such data was easily available on the Internet, I bought a big set of CDROMs of data from the Voyager missions. It included software, with source code, for displaying the image. I had fun playing with and modifying the software. It was fun seeing the images slowly rendering on the screen.

28th July 2022, 04:08 PM	#1096
ynot Philosopher Join Date: Jan 2006 Location: Present Posts: 9,214	Other than the "eye candy" images, my main lay-interests in JWST are evidence that life might exists elsewhere, and evidence that either supports The Big Bang/expanding Universe model or not. I also expect "at the length truth will out", so I don't need to worry about Standard Model bias conspiracies. I imagine (hope) there will be a deep space image that uses JWST's highest resolution and magnification at the longest exposure to see the full extent of how far it can see and what's there (well, what was there when the light/heat was emitted).
	__________________ Paranormal/supernatural beliefs are knowledge placebos. Rumours of a god’s existence have been greatly exaggerated. Make beliefs truths and you get make-believe truths. Last edited by ynot; 28th July 2022 at 04:21 PM.

2nd August 2022, 12:50 PM	#1097
ynot Philosopher Join Date: Jan 2006 Location: Present Posts: 9,214	JWST Next Steps . . . https://blogs.nasa.gov/webb/2022/08/...bs-next-steps/ ETA - Eye candy . . . https://www.nasa.gov/feature/goddard...rtwheel-galaxy . . . Yummy! JWST = Just Wow! Space Telescope
	__________________ Paranormal/supernatural beliefs are knowledge placebos. Rumours of a god’s existence have been greatly exaggerated. Make beliefs truths and you get make-believe truths. Last edited by ynot; 2nd August 2022 at 01:08 PM.

2nd August 2022, 04:21 PM	#1098
ynot Philosopher Join Date: Jan 2006 Location: Present Posts: 9,214	Oooops - wrong thread.
	__________________ Paranormal/supernatural beliefs are knowledge placebos. Rumours of a god’s existence have been greatly exaggerated. Make beliefs truths and you get make-believe truths.

4th August 2022, 04:31 AM	#1099
Jack by the hedge Safely Ignored Join Date: Oct 2009 Posts: 13,577	Does this thread about the JWST need a major split? The cosmology discussion probably deserves a thread of its own.